Dynamic Baseband Management

ABSTRACT

This disclosure relates to dynamic baseband management for a wireless device. The wireless device may be an accessory device. The accessory device may determine whether it has a short-range wireless communication link with a companion device. The accessory device may determine one or more proximity metrics relating to the companion device. The accessory device may further determine one or more metrics associated with user settings, user activity and/or application activity at the wireless device. The wireless device may select a (e.g., full, limited, or off) baseband operating mode based on any or all of these considerations.

PRIORITY CLAIM

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 15/609,668, entitled “Dynamic Baseband Management,”filed May 31, 2017, which is hereby incorporated by reference in itsentirety as though fully and completely set forth herein.

The claims in the instant application are different than those of theparent application or other related applications. The Applicanttherefore rescinds any disclaimer of claim scope made in the parentapplication or any predecessor application in relation to the instantapplication. The Examiner is therefore advised that any such previousdisclaimer and the cited references that it was made to avoid, may needto be revisited. Further, any disclaimer made in the instant applicationshould not be read into or against the parent application or otherrelated applications.

TECHNICAL FIELD

The present application relates to wireless communication, including totechniques for a wireless device to dynamically manage its basebandoperations.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. Further,wireless communication technology has evolved from voice-onlycommunications to also include the transmission of data, such asInternet and multimedia content.

Mobile electronic devices may take the form of smart phones or tabletsthat a user typically carries. Wearable devices (also referred to asaccessory devices) are a newer form of mobile electronic device, oneexample being smart watches. Typically, wearable devices have relativelylimited wireless communications capabilities and typically have smallerbatteries than larger portable devices, such as smart phones andtablets. In general, it would be desirable to reduce the powerrequirements of communication devices. Therefore, improvements in thefield are desired.

SUMMARY

Embodiments are presented herein of, inter alia, systems, apparatuses,and methods for a wireless device to dynamically manage its basebandoperations.

The wireless device may be a link budget limited device, such as anaccessory device with a relatively limited battery power capacity, e.g.,due to device design constraints. Because of the relatively limitedbattery power capacity of the wireless device, avoiding excessive poweruse for baseband operations may be a priority.

Accordingly, the wireless device may gather information that may helpwith determining when and to what degree baseband operations would beworthwhile. Among the information gathered may be one or more proximitymetrics relative to a companion device. Such proximity metrics mayinclude the connection status and quality of one or more short-rangewireless links between the wireless device and the companion device.

The wireless device may also determine one or more user activity and/orapplication activity metrics. These metrics may include one or more ofvarious metrics of the user's activity or the activity, particularlycommunication activity, of any application(s) executing on the wirelessdevice. Additionally or alternatively, any of various user settings onthe wireless device may be considered. Such activity metrics maydescribe the communication requirements necessary to support activity onthe wireless device, while the settings may relate to whether one ormore types of wireless communication have been enabled/disabled by auser of the wireless device.

Based on the information gathered by the wireless device, the wirelessdevice may determine a baseband operating mode. For example, thebaseband operating mode may be determined based on any or all of thedetermined proximity metrics, user activity metrics, applicationactivity metrics, and/or user settings. Generally, such basebandoperating modes may comprise a range of power modes, from powered off tofull-power, with various other possibilities. At least in someinstances, the selected baseband operating mode may include a minimalamount of functionality that supports the communication requests of thewireless device, e.g., in view of possible other communication optionsavailable to the wireless device. This may help reduce the powerconsumption of the wireless device, e.g., by avoiding unnecessarybaseband operations that would be redundant and/or not permitted.

The techniques described herein may be implemented in and/or used with anumber of different types of devices, including but not limited tocellular phones, tablet computers, accessory and/or wearable computingdevices, portable media players, cellular base stations and othercellular network infrastructure equipment, servers, and any of variousother computing devices.

This summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present subject matter can be obtainedwhen the following detailed description of the embodiments is consideredin conjunction with the following drawings.

FIG. 1 illustrates an example wireless communication system including anaccessory device, according to some embodiments;

FIG. 2 illustrates an example system where an accessory device canselectively either directly communicate with a cellular base station orutilize the cellular capabilities of an intermediate or proxy devicesuch as a smart phone, according to some embodiments;

FIG. 3 is a block diagram illustrating an example wireless device,according to some embodiments;

FIG. 4 is a block diagram illustrating an example base station,according to some embodiments;

FIG. 5 illustrates a possible example coverage scenario for smartphonesand smart watches, according to some embodiments;

FIG. 6 is a flowchart diagram illustrating an exemplary method for awireless device to dynamically manage its baseband operations, accordingto some embodiments;

FIG. 7 is a diagram illustrating an example logical structure formanaging wireless operations of a wireless device, according to someembodiments;

FIG. 8 is a flowchart diagram illustrating exemplary possible steps formanaging wireless operations of a wireless device using the logicalstructure of FIG. 7, according to some embodiments;

FIG. 9 illustrates a variety of possible information that may beconsidered when managing wireless operations of a wireless device,according to some embodiments;

FIGS. 10-18 are flowchart diagrams illustrating exemplary possibleprocesses for implementing wireless operating mode changes, according tosome embodiments;

FIG. 19 illustrates various possible states of an exemplary possiblebaseband management entity, according to some embodiments; and

FIGS. 20-22 are communication flow diagrams illustrating exemplarypossible communication flows that may be used as part of managingbaseband operations, according to some embodiments.

While the features described herein are susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and are herein described indetail. It should be understood, however, that the drawings and detaileddescription thereto are not intended to be limiting to the particularform disclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the subject matter as defined by the appended claims.

DETAILED DESCRIPTION Terminology

The following are definitions of terms used in this disclosure:

Memory Medium—Any of various types of non-transitory memory devices orstorage devices. The term “memory medium” is intended to include aninstallation medium, e.g., a CD-ROM, floppy disks, or tape device; acomputer system memory or random access memory such as DRAM, DDR RAM,SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash,magnetic media, e.g., a hard drive, or optical storage; registers, orother similar types of memory elements, etc. The memory medium mayinclude other types of non-transitory memory as well or combinationsthereof. In addition, the memory medium may be located in a firstcomputer system in which the programs are executed, or may be located ina second different computer system which connects to the first computersystem over a network, such as the Internet. In the latter instance, thesecond computer system may provide program instructions to the firstcomputer for execution. The term “memory medium” may include two or morememory mediums which may reside in different locations, e.g., indifferent computer systems that are connected over a network. The memorymedium may store program instructions (e.g., embodied as computerprograms) that may be executed by one or more processors.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Programmable Hardware Element—includes various hardware devicescomprising multiple programmable function blocks connected via aprogrammable interconnect. Examples include FPGAs (Field ProgrammableGate Arrays), PLDs (Programmable Logic Devices), FPOAs (FieldProgrammable Object Arrays), and CPLDs (Complex PLDs). The programmablefunction blocks may range from fine grained (combinatorial logic or lookup tables) to coarse grained (arithmetic logic units or processorcores). A programmable hardware element may also be referred to as“reconfigurable logic”.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

User Equipment (UE) (or “UE Device”)—any of various types of computersystems devices which are mobile or portable and which performs wirelesscommunications. Examples of UE devices include mobile telephones orsmart phones (e.g., iPhone™, Android™-based phones), portable gamingdevices (e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™,iPhone™), laptops, wearable devices (e.g. smart watch, smart glasses),PDAs, portable Internet devices, music players, data storage devices, orother handheld devices, etc. In general, the term “UE” or “UE device”can be broadly defined to encompass any electronic, computing, and/ortelecommunications device (or combination of devices) which is easilytransported by a user and capable of wireless communication.

Wireless Device—any of various types of computer system devices whichperforms wireless communications. A wireless device can be portable (ormobile) or may be stationary or fixed at a certain location. A UE is anexample of a wireless device.

Communication Device—any of various types of computer systems or devicesthat perform communications, where the communications can be wired orwireless. A communication device can be portable (or mobile) or may bestationary or fixed at a certain location. A wireless device is anexample of a communication device. A UE is another example of acommunication device.

Base Station—The term “Base Station” (also called “eNB”) has the fullbreadth of its ordinary meaning, and at least includes a wirelesscommunication station installed at a fixed location and used tocommunicate as part of a wireless cellular communication system.

Link Budget Limited—includes the full breadth of its ordinary meaning,and at least includes a characteristic of a wireless device (a UE) whichexhibits limited communication capabilities, or limited power, relativeto a device that is not link budget limited, or relative to devices forwhich a radio access technology (RAT) standard has been developed. A UEthat is link budget limited may experience relatively limited receptionand/or transmission capabilities, which may be due to one or morefactors such as device design, device size, battery size, antenna sizeor design, transmit power, receive power, current transmission mediumconditions, and/or other factors. Such devices may be referred to hereinas “link budget limited” (or “link budget constrained”) devices. Adevice may be inherently link budget limited due to its size, batterypower, and/or transmit/receive power. For example, a smart watch that iscommunicating over LTE or LTE-A with a base station may be inherentlylink budget limited due to its reduced transmit/receive power and/orreduced antenna. Wearable devices, such as smart watches, are generallylink budget limited devices. Alternatively, a device may not beinherently link budget limited, e.g., may have sufficient size, batterypower, and/or transmit/receive power for normal communications over LTEor LTE-A, but may be temporarily link budget limited due to currentcommunication conditions, e.g., a smart phone being at the edge of acell, etc. It is noted that the term “link budget limited” includes orencompasses power limitations, and thus a power limited device may beconsidered a link budget limited device.

Processing Element (or Processor)—refers to various elements orcombinations of elements. Processing elements include, for example,circuits such as an ASIC (Application Specific Integrated Circuit),portions or circuits of individual processor cores, entire processorcores, individual processors, programmable hardware devices such as afield programmable gate array (FPGA), and/or larger portions of systemsthat include multiple processors.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

Configured to—Various components may be described as “configured to”perform a task or tasks. In such contexts, “configured to” is a broadrecitation generally meaning “having structure that” performs the taskor tasks during operation. As such, the component can be configured toperform the task even when the component is not currently performingthat task (e.g., a set of electrical conductors may be configured toelectrically connect a module to another module, even when the twomodules are not connected). In some contexts, “configured to” may be abroad recitation of structure generally meaning “having circuitry that”performs the task or tasks during operation. As such, the component canbe configured to perform the task even when the component is notcurrently on. In general, the circuitry that forms the structurecorresponding to “configured to” may include hardware circuits.

Various components may be described as performing a task or tasks, forconvenience in the description. Such descriptions should be interpretedas including the phrase “configured to.” Reciting a component that isconfigured to perform one or more tasks is expressly intended not toinvoke interpretation under 35 U.S.C. § 112(f) for that component.

FIG. 1—Wireless Communication System

FIG. 1 illustrates an example of a wireless communication system. It isnoted that FIG. 1 represents one possibility among many, and thatfeatures of the present disclosure may be implemented in any of varioussystems, as desired. For example, embodiments described herein may beimplemented in any type of wireless device. The wireless embodimentdescribed below is one example embodiment.

As shown, the exemplary wireless communication system includes acellular base station 102, which communicates over a transmission mediumwith one or more wireless devices 106A, 106B, etc., as well as accessorydevice 107. Wireless devices 106A, 106B, and 107 may be user devices,which may be referred to herein as “user equipment” (UE) or UE devices.

The base station 102 may be a base transceiver station (BTS) or cellsite, and may include hardware that enables wireless communication withthe UE devices 106A, 106B, and 107. The base station 102 may also beequipped to communicate with a network 100 (e.g., a core network of acellular service provider, a telecommunication network such as a publicswitched telephone network (PSTN), and/or the Internet, among variouspossibilities). Thus, the base station 102 may facilitate communicationamong the UE devices 106 and 107 and/or between the UE devices 106/107and the network 100. In other implementations, base station 102 can beconfigured to provide communications over one or more other wirelesstechnologies, such as an access point supporting one or more WLANprotocols, such as 802.11 a, b, g, n, ac, ad, and/or ax, or LTE in anunlicensed band (LAA).

The communication area (or coverage area) of the base station 102 may bereferred to as a “cell.” The base station 102 and the UEs 106/107 may beconfigured to communicate over the transmission medium using any ofvarious radio access technologies (RATs) or wireless communicationtechnologies, such as GSM, UMTS (WCDMA, TDS-CDMA), LTE, LTE-Advanced(LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD),Wi-Fi, etc.

Base station 102 and other similar base stations (not shown) operatingaccording to one or more cellular communication technologies may thus beprovided as a network of cells, which may provide continuous or nearlycontinuous overlapping service to UE devices 106A-N and 107 and similardevices over a geographic area via one or more cellular communicationtechnologies.

As further shown, the exemplary wireless communication system includesmultiple satellites 108, which may provide wireless (e.g., RF) signalsto one or more wireless devices 106A, 106B, etc., as well as accessorydevice 107. The wireless signals from the satellites 108 may allow anyor all of the UEs 106/107 that are so configured to determine theirlocation information, e.g., in accordance with one or more globalnavigational satellite system (GNSS, e.g., GPS, GLONASS, Galileo,Beidou) technologies. For example, one of the UEs 106/107 mighttriangulate the longitude, latitude, and/or altitude/elevation of thedevice based on time indications from the set of satellites 108 withincommunication range of the device.

Note that at least in some instances a UE device 106/107 may be capableof communicating using any of a plurality of wireless communicationtechnologies. For example, a UE device 106/107 might be configured tocommunicate using one or more of GSM, UMTS, CDMA2000, WiMAX, LTE, LTE-A,NR, WLAN, Bluetooth, one or more GNSS technologies, one and/or moremobile television broadcasting standards (e.g., ATSC-M/H), etc. Othercombinations of wireless communication technologies (including more thantwo wireless communication technologies) are also possible. Likewise, insome instances a UE device 106/107 may be configured to communicateusing only a single wireless communication technology.

The UEs 106A and 106B are typically handheld devices such as smartphones or tablets, but may be any of various types of device withcellular communications capability. The UE 106B may be configured tocommunicate with the UE device 107, which may be referred to as anaccessory device 107, while the UE 106B associated with the accessorydevice 107 may be referred to as a companion device to the accessorydevice 107. The accessory device 107 may be any of various types ofwireless devices, typically a wearable device that has a smaller formfactor, and may have limited battery, output power and/or communicationsabilities relative to UEs 106. As one common example, the UE 106B may bea smart phone carried by a user, and the accessory device 107 may be asmart watch worn by that same user. The UE 106B and the accessory device107 may communicate using any of various short range communicationprotocols, such as Bluetooth or Wi-Fi.

The accessory device 107 includes cellular communication capability andhence is able to directly communicate with cellular base station 102.The accessory device 107 further includes GNSS communication capabilityand hence is able to directly determine accurate location informationfor the accessory device 107 based on signals received from thesatellites 108. However, since the accessory device 107 is possibly oneor more of communication, output power and/or battery limited, theaccessory device 107 may in some instances selectively utilize the UE106B as a proxy for communication purposes with the base station 102 andhence to the network 100, and/or for location determination purposeswith satellites 108. In other words, the accessory device 107 mayselectively use the cellular and/or GNSS communication capabilities ofits companion device (e.g., UE 106B) to conduct its cellular and/or GNSScommunications. The limitation on communication abilities of theaccessory device 107 can be permanent, e.g., due to limitations inoutput power or the radio access technologies (RATs) supported, ortemporary, e.g., due to conditions such as current battery status,inability to access a network, or poor reception.

FIG. 2 illustrates an example accessory device 107 in communication withbase station 102 and satellites 108, according to some embodiments. Theaccessory device 107 may be a wearable device such as a smart watch. Theaccessory device 107 may comprise cellular communication capability andbe capable of directly communicating with the base station 102 as shown.The accessory device 107 may also have GNSS communication capability andbe capable of directly communicating with the satellites 108 as shown.When the accessory device 107 is configured to directly communicate withthe base station and/or satellites 108, the accessory device may be saidto be in “autonomous mode.”

The accessory device 107 may also be capable of communicating withanother device (e.g., UE 106), referred to as a proxy device,intermediate device, or companion device, using a short rangecommunications protocol; for example, the accessory device 107 mayaccording to some embodiments be “paired” with the UE 106. Under somecircumstances, the accessory device 107 may use the cellular and/or GNSSfunctionality of this proxy device for communicating cellular voice/datawith the base station 102 and/or for determining location informationfor the paired devices from the satellites 108. For example, theaccessory device 107 may provide voice/data packets intended for thebase station 102 over the short range link to the UE 106, and the UE 106may use its cellular functionality to transmit (or relay) thisvoice/data to the base station on behalf of the accessory device 107.Similarly, the voice/data packets transmitted by the base station andintended for the accessory device 107 may be received by the cellularfunctionality of the UE 106 and then may be relayed over the short rangelink to the accessory device. As a further example, the timing signalsprovided by the satellites 108 may be received by the UE 106 and used todetermine the location of the UE 106, which may then relay the locationinformation to the accessory device 107. Note that such locationinformation may serve as approximate location information for theaccessory device 107, e.g., as the accessory device 107 may besufficiently close to the UE 106 to perform short range wirelesscommunication, but may not be as accurate as location informationobtained when the accessory device 107 utilizes its own GNSSfunctionality. As noted above, the UE 106 may be a mobile phone, atablet, or any other type of hand-held device, a media player, acomputer, a laptop or virtually any type of wireless device. When theaccessory device 107 is configured to indirectly communicate with thebase station using the cellular functionality of an intermediate orproxy device, the accessory device may be said to be in “relay mode.”

The UE 106 and/or 107 may include a device or integrated circuit forfacilitating cellular communication, referred to as a cellular modem.According to some embodiments, the cellular modem may also include GNSSfunctionality integrated into the cellular modem, though the GNSSfunctionality may be provided separately if desired. The cellular modemmay include one or more processors (processor elements) and varioushardware components as described herein. The UE 106 and/or 107 mayperform any of the method embodiments described herein by executinginstructions on one or more programmable processors. Alternatively, orin addition, the one or more processors may be one or more programmablehardware elements such as an FPGA (field-programmable gate array), orother circuitry, that is configured to perform any of the methodembodiments described herein, or any portion of any of the methodembodiments described herein. The cellular modem described herein may beused in a UE device as defined herein, a wireless device as definedherein, or a communication device as defined herein. The cellular modemdescribed herein may also be used in a base station or other similarnetwork side device.

The UE 106 and/or 107 may include one or more antennas for communicatingusing two or more wireless communication protocols or radio accesstechnologies. In some embodiments, the UE device 106 or 107 might beconfigured to communicate using a single shared radio. The shared radiomay couple to a single antenna, or may couple to multiple antennas(e.g., for MIMO) for performing wireless communications. Alternatively,the UE device 106 or 107 may include two or more radios. Otherconfigurations are also possible.

The accessory device 107 may be any of various types of devices that, insome embodiments, has a smaller form factor relative to a conventionalsmart phone, and may have one or more of limited communicationcapabilities, limited output power, or limited battery life relative toa conventional smart phone. As noted above, in some embodiments, theaccessory device 107 is a smart watch or other type of wearable device.As another example, the accessory device 107 may be a tablet device,such as an iPad, with Wi-Fi capabilities (and possibly limited cellularcommunication capabilities), which is not currently near a Wi-Fi hotspotand hence is not currently able to communicate over Wi-Fi with theInternet. Thus, as defined above, the term “accessory device” refers toany of various types of devices that in some instances have limited orreduced communication capabilities and hence may selectively andopportunistically utilize the UE 106 as a proxy for communicationpurposes for one or more applications and/or RATs. As previously noted,when the UE 106 is capable of being used by the accessory device 107 asa proxy, the UE 106 may be referred to as a companion device to theaccessory device 107.

FIG. 3—Example Block Diagram of a UE Device

FIG. 3 illustrates one possible block diagram of an UE device, such asUE device 106 or 107. As shown, the UE device 106/107 may include asystem on chip (SOC) 300, which may include portions for variouspurposes. For example, as shown, the SOC 300 may include processor(s)302 which may execute program instructions for the UE device 106/107,and display circuitry 304 which may perform graphics processing andprovide display signals to the display 360. The SOC 300 may also includemotion sensing circuitry 370 which may detect motion of the UE 106, forexample using a gyroscope, accelerometer, and/or any of various othermotion sensing components. The processor(s) 302 may also be coupled tomemory management unit (MMU) 340, which may be configured to receiveaddresses from the processor(s) 302 and translate those addresses tolocations in memory (e.g., memory 306, read only memory (ROM) 350, flashmemory 310). The MMU 340 may be configured to perform memory protectionand page table translation or set up. In some embodiments, the MMU 340may be included as a portion of the processor(s) 302.

As shown, the SOC 300 may be coupled to various other circuits of the UE106/107. For example, the UE 106/107 may include various types of memory(e.g., including NAND flash 310), a connector interface 320 (e.g., forcoupling to a computer system, dock, charging station, etc.), thedisplay 360, and wireless communication circuitry 330 (e.g., for LTE,LTE-A, NR, CDMA2000, Bluetooth, Wi-Fi, NFC, GPS, etc.).

The UE device 106/107 may include at least one antenna, and in someembodiments multiple antennas 335 a and 335 b, for performing wirelesscommunication with base stations and/or other devices. For example, theUE device 106/107 may use antennas 335 a and 335 b to perform thewireless communication. As noted above, the UE device 106/107 may insome embodiments be configured to communicate wirelessly using aplurality of wireless communication standards or radio accesstechnologies (RATs).

The wireless communication circuitry 330 may include Wi-Fi Logic 332, aCellular Modem 334, and Bluetooth Logic 336. The Wi-Fi Logic 332 is forenabling the UE device 106/107 to perform Wi-Fi communications on an802.11 network. The Bluetooth Logic 336 is for enabling the UE device106/107 to perform Bluetooth communications. The cellular modem 334 maybe a lower power cellular modem capable of performing cellularcommunication according to one or more cellular communicationtechnologies. According to some embodiments, cellular modem 334 may haveGPS and/or other GNSS functionality co-located on the same integratedcircuit (e.g., chip), as shown, though it should be noted that thisfunctionality may be provided separately if desired.

As described herein, UE 106/107 may include hardware and softwarecomponents for implementing embodiments of this disclosure. For example,one or more components of the wireless communication circuitry 330(e.g., Wi-Fi logic 332, cellular modem/GPS 334, BT logic 336) of the UEdevice 106/107 may be configured to implement part or all of the methodsdescribed herein, e.g., by a processor executing program instructionsstored on a memory medium (e.g., a non-transitory computer-readablememory medium), a processor configured as an FPGA (Field ProgrammableGate Array), and/or using dedicated hardware components, which mayinclude an ASIC (Application Specific Integrated Circuit).

FIG. 4—Block Diagram of a Base Station

FIG. 4 illustrates an example block diagram of a base station 102,according to some embodiments. It is noted that the base station of FIG.4 is merely one example of a possible base station. As shown, the basestation 102 may include processor(s) 404 which may execute programinstructions for the base station 102. The processor(s) 404 may also becoupled to memory management unit (MMU) 440, which may be configured toreceive addresses from the processor(s) 404 and translate thoseaddresses to locations in memory (e.g., memory 460 and read only memory(ROM) 450) or to other circuits or devices.

The base station 102 may include at least one network port 470. Thenetwork port 470 may be configured to couple to a telephone network andprovide a plurality of devices, such as UE devices 106/107, access tothe telephone network as described above in FIGS. 1 and 2.

The network port 470 (or an additional network port) may also oralternatively be configured to couple to a cellular network, e.g., acore network of a cellular service provider. The core network mayprovide mobility related services and/or other services to a pluralityof devices, such as UE devices 106/107. In some cases, the network port470 may couple to a telephone network via the core network, and/or thecore network may provide a telephone network (e.g., among other UEdevices serviced by the cellular service provider).

The base station 102 may include at least one antenna 434, and possiblymultiple antennas. The antenna(s) 434 may be configured to operate as awireless transceiver and may be further configured to communicate withUE devices 106/107 via radio 430. The antenna(s) 434 communicates withthe radio 430 via communication chain 432. Communication chain 432 maybe a receive chain, a transmit chain or both. The radio 430 may beconfigured to communicate via various wireless communication standards,including, but not limited to, LTE, LTE-A, NR, GSM, UMTS, CDMA2000,Wi-Fi, etc.

The base station 102 may be configured to communicate wirelessly usingmultiple wireless communication standards. In some instances, the basestation 102 may include multiple radios, which may enable the basestation 102 to communicate according to multiple wireless communicationtechnologies. For example, as one possibility, the base station 102 mayinclude an LTE radio for performing communication according to LTE aswell as a Wi-Fi radio for performing communication according to Wi-Fi.In such a case, the base station 102 may be capable of operating as bothan LTE base station and a Wi-Fi access point. As another possibility,the base station 102 may include a multi-mode radio which is capable ofperforming communications according to any of multiple wirelesscommunication technologies (e.g., LTE and Wi-Fi, LTE and UMTS, LTE andCDMA2000, UMTS and GSM, etc.).

As described further subsequently herein, the BS 102 may includehardware and software components for implementing or supportingimplementation of features described herein. The processor 404 of thebase station 102 may be configured to implement or supportimplementation of part or all of the methods described herein, e.g., byexecuting program instructions stored on a memory medium (e.g., anon-transitory computer-readable memory medium). Alternatively, theprocessor 404 may be configured as a programmable hardware element, suchas an FPGA (Field Programmable Gate Array), or as an ASIC (ApplicationSpecific Integrated Circuit), or a combination thereof. Alternatively(or in addition) the processor 404 of the BS 102, in conjunction withone or more of the other components 430, 432, 434, 440, 450, 460, 470may be configured to implement or support implementation of part or allof the features described herein.

FIG. 5—Example Coverage Range

As noted above, a wireless device may be a link budget limited device,such as an accessory device with a relatively limited communicationrange, e.g., due to device design constraints. Because of the relativelylimited communication range of the wireless device, cellularcommunication service coverage for the wireless device may not be aswidespread as for many other wireless devices, which may in turn resultin the wireless device experiencing less cellular communicationcapabilities than a wireless device with greater communication range.

FIG. 5 illustrates one possible example of a coverage scenario forsmartphones (an exemplary companion device) and smart watches (anexemplary accessory device), according to some embodiments. As shown, abase station 502 may provide a cell for a variety of wireless devices,including various smartphones 506 and various smart watches 507. Aspreviously discussed, such different types of devices may have differingcharacteristics that result in different effective communication ranges.Thus, as shown, the effective watch cell range 510 may be smaller thanthe effective smartphone cell range 520. As a result, while all of theillustrated smartphones (506A, 506B, 506C, 506D, 506E) may be have goodcommunication quality with the base station 502, only one of theillustrated smart watches (507A) may enjoy similar communicationquality, and the remainder of the illustrated smart watches (507B, 507C,507D) may have lower communication quality (e.g., and may be outside ofcommunicative range of the base station 502).

In view of the potentially more limited communication range/capabilityof an accessory device (e.g., a smart watch 507) in comparison to itscompanion device (e.g., a smartphone 506), it may commonly be preferredto utilize a relay link with a companion device for communications whensuch a link is available. Considering the potentially more limitedbattery capacity of an accessory device, it may further be helpful todynamically manage the baseband operation of an accessory device, e.g.,to limit battery consumption during times when full baseband operationis not necessary (and potentially not optimal), such as when a relaylink with a companion device can support any desired communication needsof the accessory device at a lower power cost than by the accessorydevice autonomously using its own baseband communication capabilities.

It should be noted that while the above is described as being directedto accessory devices or link budget limited devices, such techniques mayalso be beneficial to non-link budget limited wireless devices (e.g.,including wireless devices with larger cellular communication ranges,such as the smartphones illustrated in FIG. 5), and may also oralternatively be used in conjunction with such devices if desired.

FIG. 6—Flowchart

In wireless devices, particularly accessory or wearable devices,maximizing battery life, given the small form factor and, thus limitedbattery capacity, is an important consideration. Providing more dynamicmanagement of baseband operations is one possible technique topotentially improve battery life of these devices.

FIG. 6 is a flowchart diagram illustrating one such method for awireless device (e.g., an accessory device) to dynamically manage itsbaseband operations, according to some embodiments. In variousembodiments, some of the elements of the methods shown may be performedconcurrently, in a different order than shown, may be substituted for byother method elements, or may be omitted. Additional method elements mayalso be performed as desired.

Aspects of the method of FIG. 6 may be implemented by a wireless device,such as a UE 106 or 107 illustrated in and described with respect toFIGS. 1-3, or more generally in conjunction with any of the computersystems or devices shown in the above Figures, among other devices, asdesired. As shown, the method may operate as follows.

In 602, a wireless device (e.g., UE 107), may determine one or moreproximity metrics for a companion device (e.g., UE 106). The proximitymetrics determined may include any of various possible metrics relatingto the proximity (or lack of proximity) of a companion device to thewireless device. As one possibility, the wireless device may determinewhether the wireless device has a relay wireless link to a companiondevice. A relay wireless link may be made using a short-range wirelesscommunication technology, such as Bluetooth or Wi-Fi (potentially as aWi-Fi peer-to-peer link or in an infrastructure mode, e.g., via anintermediary access point). The wireless device may also determinewhether the wireless device has a wireless link to one or more Wi-Fiaccess points or cellular base stations (for example BS 102), in someembodiments.

For any wireless links available, the wireless device may also determinethe type of each such wireless link (e.g., whether it provides relaylink with a companion device, whether it provides wide area network(WAN) (e.g., Internet) connectivity, whether it is a Wi-Fi link, aBluetooth link, a cellular link (potentially including a type ofcellular technology), etc.). Such information may be useful as differentlink types may have different characteristics, and may thus affect thepreferred baseband operating characteristics.

Another possible set of proximity metrics may include the length of timefor which each such wireless link has been connected and/or the lengthof time for which each such link has not been connected. These metricsmay be useful to the wireless device by allowing it to avoid spendingenergy initiating baseband operations in instances where a short-rangewireless link is likely to be available in a short time. Basebandoperations may require time (e.g., 10 to 15 seconds, in some instances;other values are also possible) to initiate, and thus it may beinefficient to initiate baseband operations because of a momentary lossof a short-range wireless link which may have preferred operatingcharacteristics (e.g., lower power use).

At least in some instances, the wireless device may also oralternatively determine signal strength, signal quality, and/or any ofvarious other possible metrics relating to link quality for some or allavailable links. For example, for a Wi-Fi relay link via an accesspoint, any or all of RSSI, SNR, first hop packet loss, second hop packetloss, among various possible metrics, may be considered. Such metricsmay be useful to determine which link or links may be best able to meetthe performance needs of any application(s) running on the device whileavoiding excessive power usage.

At least in some instances, the wireless device may determine whether ithas a subscriber identity module (SIM) that provides a cellular serviceplan, and may potentially consider details of the cellular service plan(e.g., a carrier providing the cellular service plan, one or morelocations (e.g., mobile country codes) associated with the cellularservice plan, etc.).

In 604, the wireless device (e.g., UE 107) may determine one or moreuser activity metrics, application activity metrics, and/or usersettings. These metrics may include one or more of various metrics ofthe user's activity or the activity, particularly communicationactivity, of any application(s) executing on the wireless device.

As one possible example, the wireless device may determine activitymetrics related to the call activity or call settings on the device,such as whether the user is initiating an emergency call or anon-emergency voice call. These metrics may inform the priority given tocommunication activity and thus what wireless link(s) may be mostappropriate.

As a further example, the metrics may include whether any applicationexecuting on the wireless device is actively performing wirelesscommunication. In the instance where no application is activelyperforming wireless communication, the wireless device may determine toreduce the power usage of wireless communication circuitry.

As a further possibility, the wireless device may determine whether anyapplication is requesting the location information for the wirelessdevice. In the case that such location information is requested, awireless link able to provide accurate location information may berequired.

In some instances, the metrics may include predictions of futureactivity based at least in part on past or current activity. Forexample, the wireless device may recognize a communication activitypattern in an application and use this pattern to predict futurewireless link requirements.

As a still further example, the metrics may include a physical positionof the wireless device relative to the user of the wireless device. Forexample, a wearable wireless device such as a watch may consider ahigher performance operating mode to be preferable if the device isbeing worn (e.g., is on a user's wrist), e.g., relative to analternative case wherein it is not near the user.

As a still further example, the metrics may include the screen stateand/or device locked/unlocked state of the wireless device. For example,a screen off state and/or device locked state may be consideredrepresentative of a lower user activity level, while a screen on stateand/or device unlocked state may be considered representative of ahigher user activity level, which may in turn affect the perceivedimportance of providing a full-power baseband operating mode versus amore limited or powered off baseband operating mode.

As a still further example, the metrics may include information aboutthe activity of a companion device. For example, the wireless device mayinfer that a certain application executing on a companion device may bea predictor of future activity (or lack thereof) on the wireless device.As another example, a metric may comprise whether or not the companiondevice is connected to an external power source for battery chargingand/or the amount of charge in the battery of the companion device.

As a still further example, the metrics may include information aboutthe status of the battery of the wireless device. For example, a metricmay comprise the amount of charge in the battery. Additionally oralternatively, the wireless device may determine whether it is currentlyconnected to an outside power source (e.g., a charger). This may affectthe relative priority given to reducing power consumption; for example,reducing power consumption may be a lower priority when connected to anexternal power source than when relying on battery power reserves.

As a still further example, the metrics may include information aboutthe location of the wireless device. For example, a metric may comprisewhether the wireless device is near a location where the wireless deviceis frequently connected to an external power source for batterycharging, whether the wireless device is in a location with home orequivalent home network cellular service, roaming cellular service, orno cellular service according to a cellular service plan of the wirelessdevice, and/or any of various other location related considerations.

The wireless device may also or alternatively determine various usersettings, e.g., settings associated with cellular communicationpermission, in determining a baseband operating mode or settingsrelating to a preferred operating mode of the wireless communicationcircuitry. For example, the user settings may include whether full useof a cellular modem of the wireless device is permitted, partial use(e.g., in airplane mode) is permitted, or use of the cellular modem ofthe wireless device is not permitted. As another example, the usersettings may include whether Wi-Fi calling is permitted. Any number ofother such user settings are also possible.

According to some embodiments, the wireless device may consider some orall of the various metrics and settings described herein (among variousother possible metrics/settings) to determine a minimum functionalitylevel that would support any user-initiated activities on the wirelessdevice (e.g., and that is permitted). Such minimum functionality levelmay be used as a minimum performance threshold for selecting one or moreof the various available wireless links.

In 606, the wireless device (e.g., UE 107) may determine a basebandand/or GPS operating mode. Note that according to some embodiments,baseband cellular and GPS operations may be co-located in the wirelessdevice, and thus may be treated as such. In alternate embodiments,cellular and GPS (and/or other GNSS) functionality may be separatelyprovided in the wireless device and thus may be handled more distinctly.Several exemplary baseband and/or GPS operating modes (which may bereferred to collectively as baseband operating modes for simplicity,e.g., based on an example scenario with co-located baseband cellular andGPS functionality, while recognizing that a baseband cellular operatingmode and a GPS operating mode of a wireless device may be determinedand/or managed independently if desired) are described in thenon-limiting list below. As one of skill in the art will understand, notall possible and relevant baseband modes are described here, and otherpossible baseband operating modes are included within the scope of thepresent disclosure.

One possible baseband mode may include a baseband operating modeincluding cellular voice communication capability. Such an operatingmode may allow the device to autonomously handle voice calls withoutrelying on other wireless links, e.g., using one or more cellularcommunication technologies, such as LTE, LTE-A, NR, UMTS, GSM, CDMA2000,etc. At least according to some embodiments, such a baseband operatingmode may be capable of supporting either or both of circuit switched orpacket switched (e.g., VoLTE) voice communications. Note that any ofvarious possible power conservation features for cellular operation maybe used in conjunction with the baseband operating mode includingcellular voice communication capability, including idle discontinuousreception (IDRX), connected discontinuous reception (CDRX), and/or anyof various other possible power conservation features, e.g., duringtimes when cellular communication is not actively being performed.

A further example baseband operating mode may include cellular voice anddata communication capability. In addition to supporting voice callsusing one or more cellular communication technologies (and potentiallyusing any of various possible power conservation features for cellularoperation), such an operating mode may allow the device to perform moregeneral data exchanges (e.g., video calls, video streaming, bulkdownloads, background or foreground application refresh activities,and/or other data exchanges) without relying on other wireless links.

Further possible baseband operating modes may include one or more modesin which the wireless device does not perform cellular transmissions. Asone possibility (e.g., a camp-only or commercial mobile alert system(CMAS) mode), such an operating mode may allow the wireless device toreceive information (e.g., emergency messages such as CMAS messages) viacellular communication. As another possibility (e.g., an airplane mode),such an operating mode may not allow the wireless device to receiveinformation via cellular communication. At least according to someembodiments, the wireless device may be able to determine locationinformation for the wireless device while in either such operating mode,e.g., as GPS communication capabilities may remain available using thebaseband circuitry of the wireless device even though at least cellulartransmission capabilities may be unavailable in such operating modes.

Another possible baseband operating mode is a powered-off basebandoperating mode. For example, if no application is requesting locationinformation and all communication requirements can be met via otherlinks, a baseband-off mode may be selected.

The determination of a baseband operating mode may be based on any orall of the proximity metrics, user activity metrics, applicationactivity metrics, and/or user settings discussed above, among otherpossible considerations. In at least some examples, the basebandoperating mode may be selected in order to avoid excessive power usewhile still providing an acceptable user performance.

As a first example of baseband operating mode determination, thewireless device may consider activity metrics that indicate a minimumfunctionality level necessary to support any user-initiated activitieson the wireless device in combination with proximity metrics and aspermitted by user settings and/or a cellular service plan of thewireless device. Such a minimum functionality level may be used as aminimum performance threshold for selecting one or more of the variousavailable wireless links. Using proximity metrics, the wireless devicemay determine whether any available short-range link may be able to meetthis minimum performance threshold. In the event that the wirelessdevice determines that no available short-range link meets the minimumperformance threshold, a baseband operating mode that does meet theminimum performance threshold (assuming such a mode is permitted andsupported by a cellular service plan) may be selected. Alternatively, inthe case that one or more available wireless links do meet the minimumperformance threshold (and/or in the case that at least some cellularoperations are not permitted or not supported by a cellular serviceplan), a power-off or low-power baseband operating mode may be selected.In other words, based on considering activity metrics in relation toproximity metrics, if one or more user-initiated activities at thewireless device require functionality that is not supported by anyavailable relay wireless link, the wireless device may initiate abaseband operating mode that may be able to provide the requiredfunctionality.

As a further example, building on the previous minimum performancethreshold example, an operating mode capable of voice and datacommunication may be selected based on a combination of activity metrics(indicating a minimum performance threshold) and proximity metrics. Forexample, in the case that activity metrics indicate that both voice anddata communication are required (e.g., for a video call) and thatproximity metrics indicate that no appropriate short-range communicationlink is available, a baseband mode including cellular voice and datacommunication capability may be required.

As a further example of baseband operating mode determination, thewireless device may determine a baseband operating mode based at leastin part on whether the wireless device has a relay wireless link withthe companion wireless device and further based at least in part on thetype of the relay wireless link. For example, if the wireless device hasa Bluetooth relay link, the wireless device may select a power-offbaseband operating mode, e.g., in order to conserve energy, as theBluetooth relay link may be able to provide any wireless communicationservices requested by the wireless device. A possible exception (asfurther described subsequently herein) may include if accurate locationinformation is requested (e.g., for a fitness application), e.g., sincelocation information obtained by the companion device may relate to thelocation of the companion device rather than the wireless device itself.

As a further example, a baseband operating mode that includes voicecalling capability may be selected based at least in part on useractivity metrics and/or application activity metrics, for example, basedon call status and relevant user settings. As one possibility, wheninitiating a call via a relay link, the wireless device may alsopromptly initiate a full baseband operating mode regardless of whatshort-range links may be available, e.g., in order to increase thereliability of the call. In this case, baseband initiation may allow fora more rapid automatic (or manual) attempt to connect the call over acellular communication link if needed, e.g., should failure of a callvia the relay link occur. As another possibility, the wireless devicemay attempt the call over a relay link (e.g., via Bluetooth) ifavailable and may initiate full baseband operating mode if (e.g., after)the call fails on the relay link. Note that if desired, differentapproaches may be taken for different types of calls. For example, fullbaseband mode may be brought up in parallel with attempting a call via arelay link for an emergency call, while full baseband mode may bebrought up only after an unsuccessful call attempt via a relay link fora non-emergency call, according to some embodiments. Further, thewireless device may consider call preference settings (e.g., Wi-Fi voicecalling permission settings) in determining a baseband operating modewhen the user initiates a voice call.

As a further example of baseband operating mode determination, thewireless device may determine a baseband operating mode based at leastin part on activity metrics related to location services in combinationwith proximity metrics. For instance, an application requiring locationinformation of the wireless device may be considered a locationexception. If no other metric (e.g., no other activity metric orproximity metric), or combination of metrics, requires power-on basebandoperation, but an active application requests accurate locationinformation, power-off baseband operation may be inadequate, e.g., sincelocation information received via relay link may be accurate for thecompanion device but only approximate for the wireless device itself.Accordingly, at least in some instances, the wireless device may selecta limited baseband operating mode (e.g., an airplane mode or a camp-onlymode). Such a limited baseband operating mode may allow the wirelessdevice to reduce power consumption by not performing cellulartransmissions, while still allowing the wireless device to determineaccurate location information for the wireless device via baseband(e.g., GPS) communications. However, this exception may not be requiredfor all applications. Some applications (e.g., fitness applications, insome instances) may require high-precision location information for thewireless device itself (and thus require the location exception),however for other applications (e.g., mapping applications, in someinstances) the location of the companion device may be sufficient (andthus the exception may not be required and a power-off basebandoperating mode may be adequate). Note that these examples ofapplications that may require accurate location information or for whichapproximate location information may be sufficient are provided forillustrative purposes only, and that the relative accuracy of thelocation information requested by an application may differ at varioustimes, for different applications of similar types, and/or for differentapplication types, among various possibilities.

Note that, at least in some instances, the wireless device may determinenot to initiate a full baseband operating mode notwithstanding otherindications (e.g., other metrics), e.g., based at least in part oncellular communication permission settings. For example, in someinstances, the wireless device might determine to operate a fullbaseband operating mode with cellular voice and data communicationcapability if no relay link with a companion device or Wi-Fi link isavailable and if one or more applications have communication requests,provided user permission for cellular communication is enabled. However,if user permission for cellular communication is disabled, the wirelessdevice might instead in such a case determine to operate in apowered-off baseband operating mode (or possibly a limited powerbaseband operating mode, e.g., if required by regulations for possiblereception of emergency messages) despite the lack of a relay link with acompanion device or Wi-Fi link and the communication request(s).

FIGS. 7-22—Dynamic Baseband Management

FIGS. 7-22 and the following information are provided as beingillustrative of further considerations and possible implementationdetails relating to the method of FIG. 6, and are not intended to belimiting to the disclosure as a whole. Numerous variations andalternatives to the details provided herein below are possible andshould be considered within the scope of the disclosure.

Wearable and other accessory devices are typically smaller in formfactor and hence may be resource constrained. For example, an accessorydevice may have limited battery, processing, and/or memory resources. Inmany instances, an accessory device may have a companion device withgreater resources. For user convenience (among other possible reasons),it may be desirable for an accessory device to have a similar batterylife as its companion device, potentially despite such devices havingdiffering resources available.

In many instances, an accessory device may support multiple radiointerfaces (e.g., Bluetooth, Wi-Fi, and baseband (potentially in turnsupporting global navigational satellite system (GNSS) capabilities suchas global positioning system (GPS) and/or wireless wide area networkconnectivity such as NR, LTE-A, LTE, UMTS, GSM, etc.). At differenttimes and/or in different circumstances, different radio interfacesamong those available may be best suited to provide networkconnectivity.

Given the potential resource constraints of an accessory device, it mayaccordingly be beneficial (e.g., to potentially improve battery life tobe comparable to a companion device despite having potentially lesserbattery capacity) to utilize the radio interfaces of an accessory deviceselectively, rather than simultaneously powering all of the device'sradio interfaces throughout the day. In some instances (e.g., for someform factors), such dynamic selection of radio technologies may beessential to ensure that the battery capacity of a device can last for areasonable amount of time, such that without dynamic selection of radiotechnologies, it may not be possible to support a viable product with afull range of radio technology capability for certain form factors.

In order to support dynamic radio link selection and basebandmanagement, it may be useful to provide a central entity that canutilize cross layer metrics to help decide which radio technologies touse at which times, e.g., to provide good power efficiency while alsoproviding good user experience.

FIG. 7 is a logical diagram illustrating one such possible centralentity (e.g., RAT manager 702) that can use cross layer metrics todecide when to use Bluetooth, Wi-Fi, and cellular connectivity fortelephony services, according to some embodiments. The RAT manager 702may decide when to use a relay wireless link (e.g., with a companiondevice) versus direct cellular connectivity for voice and data on anaccessory device, potentially including enabling telephony services whenrelay service is not possible over a BT or Wi-Fi relay link. As shown,the RAT manager 702 may provide triggers to a baseband manager 704 tobring up the baseband manager 704 when needed, to indicate preferredbaseband operating mode(s) (e.g., when to use baseband for GPS usageversus when to use a relay connection for GPS connectivity), and/or toindicate a link preference (e.g., Wi-Fi versus cellular) for telephonyservices.

FIG. 8 is a flowchart diagram illustrating possible decisionmaking andcommunication relating to dynamically managing baseband operations of anaccessory device, according to some embodiments. As shown, entitiesinvolved in the decisions and the interactions may include a RAT managerentity 802, a baseband manager entity 804, and a telephony utilities(TU) application 806.

In 808, the RAT manager 802 may determine whether the baseband manager804 is needed. As previously noted, the RAT manager 802 may consider anyof a variety of metrics to determine which radio interface(s) to use ata given time. The metrics may include proximity metrics (e.g., whether aBT and/or Wi-Fi relay link with a companion device are available),whether the device is in a screen locked or screen unlocked (or otherlock/unlock) state, one or more timers relating to how recently a BTand/or Wi-Fi relay link with a companion device were available, asubscriber identity module (SIM) state of the accessory device, and/orany of various other considerations. As least in some instances (e.g.,if a reliable BT relay link is available and there are no exceptionalcircumstances), there may be no need to power up the baseband circuitryof the accessory device, and thus potentially no need for the basebandmanager 804.

In other instances, however, it may be determined that at least somebaseband functionality may be useful. Accordingly, in 810 (e.g., in suchan instance) the RAT manager 802 may assert the baseband manager 804.

In 812, the baseband manager 804 may monitor whether it has beenasserted.

In 814, upon being asserted, the baseband manager 804 may register andsubscribe with the RAT manager 802.

In 816, the RAT manager 802 may confirm that the baseband manager 804 isregistered with the RAT manager 802.

Once the baseband manager 804 is registered with the RAT manager 802, in818, the RAT manager 802 may evaluate which of various possible basebandoperating modes to use. The possible baseband operating modes mayinclude a commercial mobile alert system (CMAS) mode (e.g., in whichlimited functionality may be available), a telephony mode (e.g., inwhich cellular voice calls may be possible), or none (e.g., if basebandoperations are no longer needed), among various other possible modes.

In 820, it may be determined if the desired baseband operating mode haschanged, e.g., as a result of the evaluation in step 818. The RATmanager 802 may remain in an evaluation loop, returning to step 818, ifthe desired baseband operating mode has not changed.

In 822, if the desired baseband operating mode has changed, the RATmanager 802 may provide an operating mode update to the baseband manager804, e.g., indicating the desired baseband operating mode.

In 824, the baseband manager 804 may receive the operating mode updatefrom the RAT manager 802.

In 826, based on the operating mode update, the baseband manager mayconfigure the baseband circuitry/software/firmware in accordance withthe desired baseband operating mode. For example, baseband may beconfigured in the CMAS mode, and/or to perform telephony using VoLTE ora circuit-switched (CS) mode or possibly a Wi-Fi calling mode. Thus,this may include increasing the amount of baseband functionality,limiting the amount of functionality, or powering the baseband off,e.g., depending on the previous baseband operating mode and the updatedbaseband operating mode.

The telephony utilities application 806 may provide a phone application,e.g., providing an interface for users to dial (e.g., voice) calls viathe accessory device. Thus, in 828, the TU application 806 may receiveuser input dialing a call. As shown, the TU application 806 may receivean indication from the baseband manager of whether telephony servicesare available at the accessory device itself. Accordingly, in 830, theTU application 806 may determine whether telephony is available. Iftelephony is not available (e.g., if the RAT manager has not brought upthe baseband manager due to having a good quality relay link), in 832,the TU application 806 may dial the call using the relay link. In such acase, a companion device of the accessory device may complete the call,and may use the relay link to relay voice packets for the call to andfrom the accessory device once the call is established. If telephony isavailable, in 834, the TU application 806 may dial the call usingtelephony services provided by the accessory device itself, e.g., by wayof the baseband manager 804 as shown.

In 836, upon receiving an indication from the TU application 806 to diala call, the baseband manager 804 may determine its voice registrationstatus. As previously noted, the baseband manager 804 may be registeredfor VoLTE calling, Wi-Fi calling, or CS calling, among variouspossibilities, e.g., depending on available links, usersettings/permissions, SIM/cellular plan availability, and/or otherconsiderations.

Thus, in 838, if the baseband manager 804 is registered for VoLTEcalling, the baseband manager 804 may attempt to establish a VoLTE call.In 840, if the baseband manager 804 is registered for Wi-Fi calling, thebaseband manager 804 may attempt to establish a Wi-Fi call. In 842, ifthe baseband manager 804 is registered for CS calling, the basebandmanager 804 may attempt to establish a CS call.

As previously noted, any of a variety of (e.g., potentially cross-layer)metrics may be considered when determining which radio interface(s) touse at an accessory device at a given time. FIG. 9 is a diagramillustrating a variety of such possible metrics that may be provided toa RAT manager 902, according to some embodiments.

As shown, one possible set of metrics that may be provided to the RATmanager 902 may include proximity metrics, e.g., relating to a companiondevice to the accessory device. Such metrics may include the proximitystate of the companion device (e.g., whether or not a companion deviceto the accessory device is in proximity at all), and which type(s) ofproximity links (e.g., Bluetooth, Wi-Fi, etc., and potentially includingmultiple types) are available.

Another metric or set of metrics may include one or more debouncingtimers. A debouncing timer may record an amount of time since theaccessory device has had a relay link. In some instances, there may be adebouncing timer for each of multiple possible types of relay links(e.g., one for a BT relay link, one for a Wi-Fi relay link, as onepossibility).

A further metric or set of metrics may relate to a physical location ofthe accessory device relative to a user of the accessory device, e.g.,if the accessory device is a wearable device that is more likely toexperience active use by a user when worn in an intended location. Forexample, whether a watch is currently being worn on a user's wrist, anarmband is currently being worn on a user's arm, etc., may be consideredin determining how much baseband functionality to provide.

A still further possible set of metrics may include metrics relating toa telephony utilities application and/or existing or recent calls. Forexample, the RAT manager may consider whether a call is currentlyestablished, any telephony related user settings (e.g., whether thedevice is in airplane mode, whether cellular permission is on/off,etc.), whether the device has a valid SIM/cellular service plan, and/orany other such telephony related considerations when managing the radiointerface usage of the accessory device.

A yet further set of metrics may include whether any application and/oruser activity related exceptions are detected. For example, if anapplication (e.g., a fitness application, a mapping application, etc.)is requesting accurate location information for the accessory device, ora user-initiated activity such as use of a virtual personal assistant orother application is occurring, such activities may bias the RAT managertowards providing increased radio interface functionality to supportthose activities.

As shown, based on the various metrics considered by the RAT manager902, the RAT manager 902 may provide input to the baseband manager 904with respect to how to manage baseband operations.

Any of a variety of algorithms or processes may be used by the RATmanager 902 to determine how the baseband manager should manage thebaseband operations based on the considerations illustrated in FIG. 9(and/or various other possible considerations). FIG. 10 is a flowchartdiagram illustrating one such possible scheme for an accessory device todetermine a baseband operating mode based on such considerations,according to some embodiments.

In 1002, it may be determined whether the accessory device has a BTrelay link.

If the accessory device has a BT relay link, in 1004 it may bedetermined whether accurate location information is required by theaccessory device (e.g., if an application executing on the accessorydevice is requesting location information for the accessory device). Ifaccurate location information is required, in 1006 it may be determinedto operate the accessory device with the BT relay link on, and withbaseband operating in a limited functionality mode (e.g., an airplanemode in which the wireless device can use GPS but cannot transmit orreceive cellular signals, or a CMAS mode in which the wireless devicecan use GPS but cannot transmit cellular signals). If accurate locationinformation is not required, in 1008 it may be determined to operate theaccessory device with the BT relay link on, and with the basebandpowered off.

If the accessory device does not have a BT relay link, in 1010 it may bedetermined whether the accessory device has a Wi-Fi link. If theaccessory device has a Wi-Fi link, in 1012 it may be determined if anyof several conditions associated with at least partial baseband use inaddition to Wi-Fi are met. One such condition may include if there is noWi-Fi relay link (e.g., the Wi-Fi link does not provide a relay link tothe companion device) and the accessory device has been on the Wi-Filink (e.g., and/or has not had a BT relay link) for at least apredetermined amount of time (e.g., 30 s, as shown, or any other desiredvalue). Another such conditions may include if the accessory device hasbeen on the Wi-Fi link (e.g., and/or has not had a BT relay link) for atleast a predetermined amount of time (e.g., 5 minutes, as shown, or anyother desired value), potentially even if the Wi-Fi link provides arelay link with the companion device. A further such condition mayinclude if accurate location information is required by the accessorydevice. If no such conditions are met, in 1014 it may be determined tooperate the accessory device with the Wi-Fi link on, and with thebaseband powered off.

If any such conditions are met, however, in 1016 it may be determinedwhether Wi-Fi calling is supported and Wi-Fi conditions are consideredgood enough to support Wi-Fi calling. If Wi-Fi calling is supported andWi-Fi conditions are considered good enough to support Wi-Fi calling, in1018 it may be determined to operate the accessory device with the Wi-Filink on, and with the baseband operating in a limited functionality mode(e.g., the CMAS mode). If Wi-Fi calling is not supported or if Wi-Ficonditions are not considered good enough to support Wi-Fi calling, in1020 it may be determined to operate the accessory device with the Wi-Filink on, and with the baseband fully functional and supporting voicecommunications. Note that in this case, data communications may stillprimarily or exclusively be performed via the Wi-Fi link, if desired.

If the accessory device does not have a Wi-Fi link, in 1022 it may bedetermined if any of several conditions possibly associated with atleast partial baseband use without Wi-Fi are met. One such condition mayinclude if the accessory device has had all radios off (e.g., has nothad a BT relay link, a Wi-Fi link, or baseband powered on) for at leasta predetermined amount of time (e.g., 30 s, as shown, or any otherdesired value). Another possible condition may include if accuratelocation information is required by the accessory device. A stillfurther possible condition may include if one or more user-initiatedactivities that request wireless communication are occurring.

If any such conditions are met, the determined operating mode may stillfurther depend on which conditions are met and/or one or more usersettings at the accessory device. In 1028, if telephony is enabled, andone or more of the conditions are met, it may be determined to operatethe accessory device with the baseband fully functional and supportingvoice and data communications. In 1030, if telephony is disabled, and atleast a location request is asserted, it may be determined to operatethe accessory device with the baseband operating in a limitedfunctionality mode (e.g., airplane mode and/or CMAS mode). In 1032, iftelephony is disabled, and no location request is asserted, and/or ifnone of the conditions are met, it may be determined to operate theaccessory device with all radios off.

FIGS. 11-18 are flowchart diagrams illustrating possible processes a RATmanager to use to determine whether to assert a baseband manager, and toevaluate which baseband operating mode to use, in accordance withvarious example scenarios.

In FIG. 11, in 1102, an accessory device may initially be in BTproximity to a companion device. In 1104, a status update may bereceived indicating that the BT relay link has been lost. In 1106, itmay be determined whether a Wi-Fi proximity link is available. In 1108,if a Wi-Fi proximity link is available, a 5 minute debouncing timer maybe started. In 1110, if no proximity link is available, a 30 seconddebouncing timer may be started.

In 1112, the RAT manager may monitor whether the debouncing timer hasexpired. In 1114, if the timer has not yet expired, the RAT manager maymonitor whether the accessory device has gained a Wi-Fi proximity linkwith the companion device. In 1116, if a Wi-Fi proximity link has beengained and a location exception is received, or in 1118, if a Wi-Fiproximity link has not been gained but any exception is received, oronce the debouncing timer has expired, the RAT manager may proceed tostep 1120, in which the baseband manager may be asserted. In 1122, theRAT manager may evaluate which baseband operating mode is desired, andin 1124, the RAT manager may send a notification of which basebandoperating mode is desired to the baseband manager.

In FIG. 12, in 1202, an accessory device may initially have Wi-Fi andcellular baseband operations active. In 1204, a status update may bereceived indicating that a BT relay link has been connected. In 1206, a30 second debouncing timer may be initiated. In 1208, it may bedetermined whether the debouncing timer has expired. Once it hasexpired, in 1210, the RAT manager may evaluate which baseband operatingmode is desired. In 1212, the RAT manager may send a notification ofwhich baseband operating mode is desired to the baseband manager. Incase the desired operating mode is baseband powered off, in 1214 the RATmanager may unassert the baseband manager.

In FIG. 13, in 1302, an accessory device may initially have basebandoperating in CMAS=ON, telephony=ON mode. In 1304, a SIM state update maybe received. In 1306, it may be determined if the SIM state updateincluded deactivating an eSIM of the accessory device. If so, in 1308,the RAT manager may determine to operate with CMAS=OFF, telephony=ONmode, and in 1310, the RAT manager may send an operating modenotification to the baseband manager indicating the change to theoperating mode.

In FIG. 14, in 1402, an accessory device may initially have basebandoperating in CMAS=OFF, telephony=ON mode. In 1404, a SIM state updatemay be received. In 1406, it may be determined if the SIM state updateincluded activating an eSIM of the accessory device. If so, in 1408, theRAT manager may determine to operate with CMAS=ON, telephony=ON mode,and in 1410, the RAT manager may send an operating mode notification tothe baseband manager indicating the change to the operating mode.

In FIG. 15, in 1502, an accessory device may initially have basebandoperating in CMAS=ON, telephony=ON mode. In 1504, a lock state changeindication may be received. In 1506, it may be determined if the lockstate change indication included indicating that the device is locked.If so, in 1508, the RAT manager may determine to operate with CMAS=ON,telephony=OFF mode, and in 1510, the RAT manager may send an operatingmode notification to the baseband manager indicating the change to theoperating mode.

In FIG. 16, in 1602, an accessory device may initially have basebandoperating in CMAS=ON, telephony=OFF mode. In 1604, a lock state changeindication may be received. In 1606, it may be determined if the lockstate change indication included indicating that the device is unlocked.If so, in 1608, the RAT manager may determine to operate with CMAS=ON,telephony=ON mode, and in 1610, the RAT manager may send an operatingmode notification to the baseband manager indicating the change to theoperating mode.

In FIG. 17, in 1702, an accessory device may initially have a BTproximity link with baseband powered off. In 1704, a location exceptionmay be received. In 1706, the RAT manager may assert the basebandmanager. In 1708, the RAT manager may evaluate which baseband operatingmode to select. In 1710, the RAT manager may send an operating modenotification to the baseband manager indicating the selected basebandoperating mode.

In FIG. 18, in 1802, an accessory device may initially have a BTproximity link with baseband powered on, e.g., due to a locationexception. In 1804, the location exception may be removed. In 1806, theRAT manager may evaluate which baseband operating mode to select. In1808, the RAT manager may send an operating mode notification to thebaseband manager indicating the selected baseband operating mode. In1810, the RAT manager may unassert the baseband manager.

FIG. 19 includes a state diagram illustrating various possible basebandoperating states that may be implemented by a baseband manager (e.g.,upon being asserted by a RAT manager and receiving instructions from theRAT manager), according to some embodiments. Upon being asserted, in1910, the baseband manager may initialize, and once initialized, in1920, may be active. Once active, the baseband manager may transitionbetween an initial state 1922, a baseband not booted state 1924, abaseband booted (airplane mode) state 1926, and a baseband booted(online) state 1928. As shown, in some embodiments, the BB not bootedstate 1924 may be skipped and the baseband manager may transition fromthe initial state 1922 directly to the baseband booted (airplane mode)state 1926. Additionally, note that in some embodiments, the basebandmanager may directly consider any of various possible mode heuristics todetermine state transitions to perform, e.g., in addition or as analternative to receiving instructions regarding the baseband operatingstate from the RAT manager. Such heuristics may be based on power (e.g.,batter reserves), current/upcoming data usage, companion proximity,command-line overrides, and/or any of various other possible inputs. In1930, (e.g., if so instructed/if unasserted by the RAT manager), thebaseband manager may begin shut down and exit.

According to some embodiments, an accessory device may include acommunication center (“CommCenter”) daemon that launches and managesvarious modules used to support cellular voice and data communications.A baseband manager such as previously described herein may be one suchmodule. A phone service module may be another such module. An IPmultimedia subsystem (IMS) stack (e.g., for VoLTE and Wi-Fi calling) maybe another such module. A data module for managing packet data network(PDN) connections (e.g., for cellular and Wi-Fi radios) may be a stillfurther such module.

The baseband manager may be responsible for many of the basebandplatform services, such as boot-up, interprocessor communication, trace,coexistence considerations, etc. The baseband manager may support aframework that provides interfaces to clients (e.g., applicationsexecuting at an application processor of the accessory device) toperform baseband related communications. At least in some instances, thebaseband manager may be configured such that it is not required whencellular service is not required, such that it may be brought down(e.g., to save power at the baseband chip, and/or to save memory at theapplication processor RAM). Thus, it may be the case that the basebandmanager supports starting and stopping its services on-demand. TheCommCenter may use the baseband manager's application program interfaces(APIs) to start/stop its operation.

FIGS. 20-22 are communication flow diagrams illustrating possibleintermodule communication in a wireless device that utilizes acommunication center daemon and baseband manager module under themanagement of the communication center daemon to manage basebandoperations.

FIG. 20 illustrates a communication flow that might occur when thecommunication center is not yet launched but its launch is requested. Asshown, the communication center may be launched and may transition froman idle state to an active state by creating all modules under itsmanagement. In starting all modules, the communication center mayinitiate the baseband manager, which may create its baseband managerserver and start interprocessor communication (IPC) service. Thebaseband manager may report its successful initiation to thecommunication center. Without further instruction, the baseband managermay remain in a stopped state, and the baseband state may remain down.

FIG. 21 illustrates a communication flow that might occur when thecommunication center is launched and baseband operation is requested. Asshown, the communication center may provide a grab baseband assertion,and may provide a trigger to the baseband manager (which may be in astopped state) to begin starting. In response, the baseband manager maycreate all modules under its management, and may bootup the baseband(which may have been down), and, once booted (e.g., in airplane mode, atleast initially), engage interprocessor communication. At this point,the baseband manager may be started, and may provide an acknowledgementto the communication center, which may recognize that the baseband stateis now booted.

If full baseband operation is requested, the communication center mayfurther provide a request for online mode to the baseband manager, whichmay in turn provide a request for online mode to the baseband. Thebaseband may transition from the booted (airplane) state to the booted(online state), and may acknowledge that it has transitioned to thebooted (online) state to the baseband manager, which may in turnacknowledge that baseband has transitioned to the booted (online) stateto the communication center.

FIG. 22 illustrates a communication flow that might occur when thecommunication center is launched and baseband is booted, but baseband isno longer required. As shown, the communication center may provide arelease baseband assertion, and may provide a trigger to the basebandmanager (which may be in a started state) to begin stopping. Inresponse, the baseband manager may provide a power off request to thebaseband, which may power down from the booted state to being down. Thebaseband manager may destroy all modules under its management At thispoint, the baseband manager may be stopped, and may provide anacknowledgement to the communication center, which may recognize thatthe baseband state is now down.

Another consideration for an accessory device that may at least on someoccasions be near a companion device may include how to handle emergencycalling. Since both devices may be capable of dialing an emergency call,possibly each using any of multiple possible techniques (e.g., circuitswitched cellular, packet switched cellular, Wi-Fi, etc.), determiningwhich technique(s) to use in which scenarios may be non-trivial.Further, due to the potentially substantially higher priority (andpotentially different handling/permission by carriers) of emergencycalls relative to other calls, at least in some instances, emergencycalling may trigger different radio interface usage than other deviceusage.

According to some embodiments, if an accessory device has a BT relaylink with a companion device, an initial attempt to establish anemergency call may be made using the companion device by way of the BTrelay link. This may often be preferable as the companion device mayoften have a better antenna, higher power, and/or other characteristicsimproving the likelihood of successfully establishing the call. However,in case the companion's call fails (or the BT relay link fails), it maybe desirable to bring up the accessory device's own baseband circuitry(e.g., in case it was off) at the same time as (e.g., in parallel with)the companion's attempt to establish the emergency call. This may allowthe accessory device to more quickly (e.g., as an automatic redial, orin case of a further attempt to dial the emergency call by the user)attempt to establish the emergency call using its own basebandcapability if needed. Note that while this process may differ fromhanding of non-emergency calls (e.g., baseband voice capability mayremain off during a non-emergency call if a BT relay link to a companiondevice exists) in some instances, in other instances baseband may bebrought up in parallel for non-emergency calls as well. Additionally, itshould be noted that bringing up an additional radio interface as afallback option for a call may be useful for potential handover of thecall, e.g., in case one radio interface fails while the call is ongoing,which may allow the accessory device to avoid at least some call drops.

As an alternative to bringing up the accessory device's baseband voicecapability in parallel with attempting an emergency call via a BT relaylink with a companion device (and/or potentially as a technique fornon-emergency calls), the accessory device's baseband may be brought upas a fallback option upon (e.g., after) failure of a call using a BTrelay link with a companion device. Thus, the call may be automaticallyredialed, or may be redialed in response to user input, using thebaseband functionality. This may reduce the power consumption of theaccessory device, e.g., as the accessory device may be able to avoidunnecessarily consuming power to bring up its baseband in instances whencalls using a BT relay link with a companion device are successful, butmay increase the time required to complete calls in instances when usinga BT relay link with a companion device is unsuccessful, and/or may leadto call failure if the BT relay link fails during a call.

A further modification to radio interface management associated withemergency calling may relate to when an accessory device does not have avalid (e)SIM/does not have a cellular service plan. At least in someinstances, the accessory device may at least partially limit basebandoperation or power off its baseband circuitry if the accessory devicedoes not have a valid SIM/cellular service plan, e.g., under normalcircumstances. However, if user input initiating an emergency call isreceived, the accessory device may bring online at least voice basebandfunctionality and attempt to establish the emergency call even thoughthe accessory device does not have a SIM or cellular service plan.

Reference is made herein to possible limited functionality basebandoperating modes, potentially including an airplane mode (e.g., in whicha wireless device may not transmit or receive cellular communications)and/or a camp-only or CMAS mode (e.g., in which a wireless device maynot transmit cellular communications, though the wireless device maystill be able to receive at least some cellular communications, such asCMAS messages). Such operating modes may consume less power than fullerfunctionality baseband operating modes, such as voice capable or voiceand data capable operating modes in which a wireless device can bothtransmit or receive cellular communications. For example, the manner inwhich the baseband communication circuitry operates may be modified toreduce power consumption. This may potentially include optimizingoperation for the reception only of emergency (e.g., CMAS) messages(e.g., including preventing other operations and/or discarding otherpages/requests/signals), reducing signaling burden for periodicre-registrations (e.g., attach, detach, tracking area updates (TAUs,routing area updates (RAUs), location area updates (LAUs), etc.), anincreased idle discontinuous reception (IDRX) cycle length, reducedfrequency and/or scope of neighbor cell measurements, modified signalstrength and/or signal quality threshold(s) for various purposes, and/orany other desired modifications in camp-only/CMAS mode. Note that, atleast according to some embodiments, it may be possible for an accessorydevice with GPS capable baseband circuitry to use the GPS functionalityin both airplane mode and in CMAS mode.

In addition to the above-described exemplary embodiments, furtherembodiments of the present disclosure may be realized in any of variousforms. For example some embodiments may be realized as acomputer-implemented method, a computer-readable memory medium, or acomputer system. Other embodiments may be realized using one or morecustom-designed hardware devices such as ASICs. Still other embodimentsmay be realized using one or more programmable hardware elements such asFPGAs.

In some embodiments, a non-transitory computer-readable memory mediummay be configured so that it stores program instructions and/or data,where the program instructions, if executed by a computer system, causethe computer system to perform a method, e.g., any of a methodembodiments described herein, or, any combination of the methodembodiments described herein, or, any subset of any of the methodembodiments described herein, or, any combination of such subsets.

In some embodiments, a device (e.g., a UE 106 or 107) may be configuredto include a processor (or a set of processors) and a memory medium,where the memory medium stores program instructions, where the processoris configured to read and execute the program instructions from thememory medium, where the program instructions are executable toimplement any of the various method embodiments described herein (or,any combination of the method embodiments described herein, or, anysubset of any of the method embodiments described herein, or, anycombination of such subsets). The device may be realized in any ofvarious forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

What is claimed is:
 1. An accessory wireless device, comprising:wireless communication circuitry, comprising at least cellularcommunication circuitry and short-range wireless communicationcircuitry; and one or more processing elements coupled to the wirelesscommunication circuitry, wherein the one or more processing elements areconfigured to cause the accessory wireless device to: determine whetherthe accessory wireless device has a short-range wireless communicationlink with a companion wireless device; determine one or more metricsassociated with user activity or application activity at the accessorywireless device; and determine whether to limit functionality of thecellular communication circuitry based at least in part on (a) whetherthe accessory wireless device has a short-range wireless communicationlink with a companion wireless device and (b) the one or more metricsassociated with user activity or application activity at the accessorywireless device.
 2. The accessory wireless device of claim 1, wherein,if the accessory wireless device has a short-range wirelesscommunication link with a companion wireless device, the one or moreprocessing elements are further configured to cause the accessorywireless device to: determine a type of the short-range wirelesscommunication link; and determine whether to limit functionality of thecellular communication circuitry further based at least in part on thetype of the short-range wireless communication link.
 3. The accessorywireless device of claim 1, wherein if the accessory wireless devicedoes not have a short-range wireless communication link with a companionwireless device, the one or more processing elements are furtherconfigured to cause the accessory wireless device to: determine a lengthof time for which the accessory wireless device has not had ashort-range wireless communication link with a companion wirelessdevice; and determine whether to limit functionality of the cellularcommunication circuitry further based at least in part on the length oftime for which the accessory wireless device has not had a short-rangewireless communication link with a companion wireless device.
 4. Theaccessory wireless device of claim 1, wherein the one or more metricsassociated with user activity or application activity at the accessorywireless device comprise at least whether any application executing atthe accessory wireless device is currently actively performing wirelesscommunication.
 5. The accessory wireless device of claim 1, wherein theone or more metrics associated with user activity or applicationactivity at the accessory wireless device comprise one or more of: aphysical position of the accessory wireless device relative to a user ofthe accessory wireless device; a screen state of the accessory wirelessdevice; or one or more user settings relating to a preferred operatingmode of the wireless communication circuitry.
 6. The accessory wirelessdevice of claim 1, wherein the one or more processing elements arefurther configured to cause the accessory wireless device to: determinewhether the accessory wireless device has a subscriber identity modulethat provides a cellular service plan, determine whether to limitfunctionality of the cellular communication circuitry further based atleast in part on whether the accessory wireless device has a subscriberidentity module that provides a cellular service plan.
 7. A method,comprising: at an accessory device: determining whether the accessorydevice has a short-range wireless communication link with a companiondevice; determining, if the accessory device does not have a short-rangewireless communication link with a companion device, a length of timefor which the accessory device has not had a short-range communicationlink with a companion device; and determining a cellular basebandoperating mode based at least in part on whether the accessory devicehas a short-range wireless communication link with a companion deviceand, if the accessory device does not have a short-range communicationlink with a companion device, further based at least in part on thelength of time for which the accessory device has not had a short-rangecommunication link with a companion device.
 8. The method of claim 7,wherein, if the accessory device has a short-range wirelesscommunication link with a companion device, the cellular basebandoperating mode is further determined based at least in part on a type ofthe short-range wireless communication link.
 9. The method of claim 7,wherein the cellular baseband operating mode is further determined basedat least in part on one or more metrics associated with user settings,user activity or application activity at the accessory device.
 10. Themethod of claim 7, wherein determining the cellular baseband operatingmode further comprises: determining to limit baseband functionality ofthe accessory device if the accessory device has a short-range wirelesscommunication link with a companion device
 11. The method of claim 7,wherein determining the cellular baseband operating mode furthercomprises: determining to limit baseband functionality of the accessorydevice if a length of time for which the accessory device has not had afirst type of short-range communication link with a companion device isless than a first threshold or if a length of time for which theaccessory device has not had a second type of short-range communicationlink with a companion device is less than a second threshold.
 12. Themethod of claim 7, wherein the cellular baseband operating mode isfurther determined based on a SIM state update.
 13. An apparatus,comprising: one or more processing elements, wherein the one or moreprocessing elements are configured to cause an accessory wireless deviceto: determine a status of a first relay wireless link with a companionwireless device; initiate a debounce timer associated with the firstrelay wireless link; determine at least one user setting metric, useractivity metric or activity metric; and determine a cellular basebandoperating mode based at least in part on: (a) the status of the firstrelay wireless link with the companion wireless device, (b) a value ofthe debounce timer, and (c) the at least one user setting metric, useractivity metric or activity metric.
 14. The apparatus of claim 13,wherein the one or more processing elements are further configured tocause the accessory wireless device to: determine a type of the firstrelay wireless link, wherein the type of the first relay wireless linkcomprises one of a Bluetooth relay link or a Wi-Fi relay link, whereinthe cellular baseband operating mode is further based at least in parton the type of the first relay wireless link.
 15. The apparatus of claim14, wherein the first relay wireless link is a Bluetooth relay link,wherein the one or more processing elements are further configured tocause the accessory wireless device to: receive user input initiating anemergency call; attempt to connect the emergency call using theBluetooth relay link; select a full cellular baseband operating modebased at least in part on receiving the user input initiating theemergency call; and automatically attempt to connect the emergency callusing a cellular communication link if the attempt to connect theemergency call using the Bluetooth relay link is unsuccessful.
 16. Theapparatus of claim 14, wherein the first relay wireless link is aBluetooth relay link, wherein the one or more processing elements arefurther configured to cause the accessory wireless device to: receiveuser input initiating a voice call; attempt to connect the voice callusing the Bluetooth relay link; determine that the attempt to connectthe voice call using the Bluetooth relay link is unsuccessful; select afull cellular baseband operating mode based at least in part ondetermining that the attempt to connect the voice call using theBluetooth relay link is unsuccessful; and automatically attempt toconnect the voice call using a cellular communication link based atleast in part on determining that the attempt to connect the voice callusing the Bluetooth relay link is unsuccessful.
 17. The apparatus ofclaim 14, wherein the first relay wireless link is a Wi-Fi relay link,wherein the one or more processing elements are further configured tocause the accessory wireless device to: determine if at least onecondition associated with at least partial cellular baseband operationsin addition to Wi-Fi is met.
 18. The apparatus of claim 13, wherein, inresponse to determining that the status of the first relay wireless linkis not connected, the one or more processing elements are furtherconfigured to cause the accessory wireless device to: determine a statusof a second relay wireless link, wherein the status of the second relaywireless link is connected; and initiate a second debounce timerassociated with the second relay wireless link, wherein the cellularbaseband operating mode is further based at least in part on a value ofthe second debounce timer.
 19. The apparatus of claim 13, wherein todetermine the cellular baseband operating mode, the one or moreprocessing elements are further configured to cause the accessorywireless device to: select a cellular baseband operating mode having aminimum functionality level that supports any user-initiated activitiesat the accessory wireless device that are not also supported by a relaywireless link with a companion wireless device or an alternatecommunication link.
 20. The apparatus of claim 13, wherein determiningthe at least one user activity metric or activity metric comprises adetermination that the accessory device is in a locked state, whereinthe cellular baseband operating mode does not include telephony.